Conveyor roller assembly

Abstract

An elongated cylindrical roller tube is rotatably supported between frame members by a pair of bearing units secured to opposite end portions of the tube. Each bearing unit includes a tubular shaft supporting a hexagonal stub axle for axial movement between an outwardly projecting position engaging a frame member and an inwardly retracted position against the bias of a coil spring confined within the shaft. An anti-friction bearing is mounted on the tubular shaft and is retained within the roller tube by an annular adapter. An annular dust cover snap-fits onto the outer end portion of the tubular shaft for protecting the bearing, and the stub axle is retained within the shaft by detents which permit pulling the stub axle from the shaft for axle replacement. The axle, shaft, adapter and cover are each molded of an electrically conductive plastics material, and each hexagonal stub axle has a resilient outer, surface and a tapered and twisted outer tip portion extending from a slightly tapered portion for self-alignment of the axles with mating hexagonal holes within the frame members.

What is claimed is: 
     
       1. A conveyor roller assembly comprising an elongated roller tube having opposite end portions, a tubular shaft member disposed within each said end portion of said roller tube, a bearing confined within the corresponding said end portion of said roller tube to provide for rotation of said roller tube relative to said shaft member, a stub axle supported within each said shaft member for axial movement between an extended position with a portion of said stub axle projecting from an outer end of said shaft member and a retracted position within said shaft member, a spring within each shaft member and urging each said stub axle to said extended position, and each said shaft member and the corresponding said stub axle including a static electrical conductive non-metallic material. 
     
     
       2. A roller assembly as defined in claim 1 wherein each said stub axle is removable from said outer end of the corresponding said shaft member in response to pulling axially on said projecting portion of said stub axle. 
     
     
       3. A roller assembly as defined in claim 1 wherein each said tubular shaft member has a cylindrical outer end portion surrounding said stub axle and projecting through the corresponding said bearing, and each said outer end portion has circumferentially spaced slots providing for slightly collapsing said outer end portion for receiving said bearing. 
     
     
       4. A roller assembly as defined in claim 3 and including an annular dust cover mounted on said outer end portion of each said shaft member for protecting the corresponding said bearing, and each said dust cover includes a ring portion surrounding a tip portion of the corresponding said shaft member. 
     
     
       5. A roller assembly as defined in claim 1 wherein each said tubular shaft member has a hexagonal inner opening slidably receiving the corresponding said stub axle and defines an internal shoulder, and each said stub axle has a slightly collapsible inner end portion engaging said shoulder in response to said spring when said axle is in said extended position. 
     
     
       6. A roller assembly as defined in claim 5 wherein said inner end portion of each said stub axle moves inwardly in response to pulling said stub axle outwardly from the corresponding said shaft member. 
     
     
       7. A roller assembly as defined in claim 5 wherein said spring comprises a coil spring adapted to engage said shoulder when said stub axle is pulled from said shaft member for retaining said spring within said shaft member when said stub axle is removed. 
     
     
       8. A roller assembly as defined in claim 1 wherein each said stub axle has a hexagonal cross-sectional configuration and a tapered and twisted outer tip portion with a smaller hexagonal cross-sectional configuration. 
     
     
       9. A roller assembly as defined in claim 8 wherein each said stub axle has a slightly tapered hexagonal portion extending from said tip portion. 
     
     
       10. A roller assembly as defined in claim 1 wherein said projecting portion of each said stub axle has a resilient outer surface. 
     
     
       11. A conveyor roller assembly comprising an elongated roller tube having opposite end portions, a tubular shaft member disposed within each said end portion of said roller tube, a bearing supported by each said shaft member and confined within the corresponding said end portion of said roller tube to provide for rotation of said roller tube relative to said shaft member, a stub axle supported within each said shaft member for axial movement between an extended position with a portion of said stub axle projecting from an outer end of said shaft member and a retracted position within said shaft member, a spring within each said shaft member and urging the corresponding said stub axle to said extended position, and each said stub axle being removable from said outer end of the corresponding said shaft member in response to pulling axially on said projecting portion of said stub axle. 
     
     
       12. A roller assembly as defined in claim 10 wherein each said tubular shaft member has a cylindrical outer end portion surrounding the corresponding said stub axle and projecting through the corresponding said bearing, and each said outer end portion has circumferentially spaced slots defining spring fingers which collapse slightly for receiving said bearing. 
     
     
       13. A roller assembly as defined in claim 12 and including an annular dust cover mounted on said spring fingers of each said shaft member for protecting the corresponding said bearing, and each said dust cover includes a ring portion surrounding an outer tip portion of the corresponding said shaft member. 
     
     
       14. A roller assembly as defined in claim 11 wherein each said tubular shaft member has a hexagonal inner chamber slidably receiving the corresponding said stub axle and defining an internal shoulder, and each said stub axle member has a slightly collapsible inner end portion opposing said shoulder when said stub axle is in said extended position. 
     
     
       15. A roller assembly as defined in claim 14 wherein said inner end portion of each said stub axle has spring tabs which move inwardly in response to pulling said stub axle outwardly from the corresponding said shaft member. 
     
     
       16. A roller assembly as defined in claim 14 wherein each said spring comprises a compression coil spring confined within of the corresponding said tubular shaft member, and said coil spring engages said shoulder when said stub axle member is pulled from said shaft member for retaining said spring within said shaft member when said stub axle is removed. 
     
     
       17. A roller assembly as defined in claim 11 wherein each of said stub axles has a hexagonal cross-sectional configuration and a tapered and twisted outer tip portion with a smaller hexagonal cross-sectional configuration. 
     
     
       18. A roller assembly as defined in claim 13 wherein each said stub axle has a slightly tapered hexagonal portion extending from said tip portion. 
     
     
       19. A roller assembly as defined in claim 11 wherein said projecting portion of each said stub axle has a resilient outer surface. 
     
     
       20. A conveyor roller assembly comprising an elongated roller tube having opposite end portions, a bearing supported within each said end portion of said roller tube to provide for rotation of said roller tube, a tubular shaft member supported within each of said bearings, a hexagonal stub axle supported within each said shaft member for axial movement and having an outer portion projecting from the corresponding said shaft member, and said outer portion of at least one if said stub axles having a tapered and twisted outer tip portion with a smaller hexagonal cross-sectional configuration. 
     
     
       21. A roller assembly as defined in claim 20 wherein each said stub axle has a slightly tapered hexagonal portion extending from said tip portion. 
     
     
       22. A roller assembly as defined in claim 20 wherein said projecting portion of each said stub axle has a resilient outer surface. 
     
     
       23. A conveyor roller assembly comprising an elongated roller tube having opposite end portions, a bearing supported within each said end portion of said roller tube to provide for rotation of said roller tube, a tubular shaft member supported within each of said bearings, a stub axle supported within each said shaft member for axial movement and having an outer portion projecting from the corresponding said shaft member, and said outer portion of each said stub axles having a resilient outer surface.